Testing an Instrument cluster?

[bobswei]

Picked up a cheap 987 Boxster with tip that had electrical issues. I posted in the past, and was lead to the rear control module. Yes, it was fried from fresh water damage. Have the new one in, a friend connected to his PIWIS to read codes (still had tail lights on all the time) and the instrument cluster went completely dead and front cooling fans on high all the time (while connected to piwis). I want to focus on the instruments right now. So far, I have 12V to the fuse box and continuing to the cluster. Next step is to check for ground. Can I test while still in the dash? I've removed clusters from 997 and a 991 in the past and pretty easy. Just wondering if there's a test while still in the car? Where is the cluster grounded? Diagram says "center of middle support frame" for ground. Huh?
The cluster has no power at all, no lights, no blinkers, no fuel level, no shift indicator, nothing. Anyone with experiance testing?
Thanks for any suggestions.

[bobswei]

OK, I figured out how to bench test an intrument cluster.* I removed it from the car. There's many threads that cover that. Then, from the wiring diagram, there were two 12v pins and two grounds.* I found that pins 1 (ground) and 2 (12v) were the ones I needed. I made a tiny pigtail that would plug in. Here are the photos that shows the setup.* Now I know it works, why not in the car? Hopefully, will help someone in the future.*

[Zacharyholl]

Push and release the Sel/reset button button 3 times repeatedly. The instrument cluster begins its self-test. Each successive press of the Sel/reset button initiates a new cycling of all the gauges. To end, turn the ignition switch to OFF, or vehicle speed exceeds 1.5 mph. DQFanSurvey.com